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G. ROBINSON. v Process and Apparatus for Treating Tobacco.

No; 230.061. Patented July 13, 1880.

P IIH \Q HIHIIIMH WITNESSES: INVENTOR:

UNITED STATES PAT NT Fluent,

, GOLDSBOROUGH ROBINSON, OF LOUISVILLE, KENTUCKY, ASSIGNOR TO LOUISVILLELEAF TOBACCO COMPANY, OF SAME PLACE.

PROCESS AND APPARATUS FOR TREATING TOBACCO.

SPECIFICATION forming part of Letters Patent No. 230,061, dated July 13,1880.

.Application filed February 24, 1880. I

To all whom it may concern:

Be it known that I, GOLDSBOROUGH Ron- INsON, of Louisville, in thecounty of Jefferson and State of Kentucky, have invented an Improvementin Processes and Apparatus for Treating Tobacco; and I do hereby declarethat the following is a full, clear, and exact description of the same,reference being had to the accompanying drawing, forming part of thisspecification, in which the figure is a side elevation with parts of theseveral receptacles broken away.

My invention relates to a novel process and apparatus designedespecially for drying leaftobacco after saturation with alcohol forimproving its color and quality, but applicable generally to therecovery 'of any volatile liquid which has been used in the treatment of1 another substance to which it adheres.

In order that the details of this invention may be better understood, Iwill describe the process as applied in connection with my process forimproving the color and quality of leaf tobacco, patented March 9, 1880,No. 225,422.

In this process I saturate the tobacco with alcohol at an elevatedtemperature, and then dry it by a blast of air, whereby the color of thedark leaf is raised to a bright hue and its market value and qualityenhanced. In using this process, however, the volatile character. ofalcohol, augmented by the elevation in temperature, requires somespecial process to save or recover the alcohol and render the processeconomical.

To this end my process consists in evaporating the alcohol orothervolatile liquid from the tobacco (or other substances treated) by ablast of air, condensing the volatile vapors by a reduced temperature,and returning the same body of air through the evaporating-chamberagain, whereby the same body of air is made to carry off the alcoholfrom the tobacco, and after depositing its burden of the volatile liquidis used over and over again without allowing any appreciable amount ofalcohol to escape into the open air.

In carrying out my process I employ an apparatus similar to that shownin the drawing,

5 in which A represents the fan or blower which propels the air-current.

B B are outlet-pipes from the fan, through either of which the blast maybe directed at will by means of the blast-gates G C.

E is a continuation of one of the dischargepipes from the blower, whichis used when a cold blast is desired, and D is a steam-coil heater,throughwhich the air-blast is directed V when a hot blast is required.

F F are other blast-gates with cords and pulleys for raising the same.

G is the dipping and drying chamber, in the bottom of which is placedthe alcohol.

H is a hanging door to'the dipping-chamber, fastened by keys andstaples.

I is the rigging for suspending the door, consisting of a set of pulleysand a track for pulling the door out and running it to one side.

K K are the hanging racks carrying the bunches of tobacco, and flexiblyconnected by chains or otherwise, so that they can be lowered into thealcohol.

J are rods passing through stuffing-boxes in the case of thedipping-chamber, and connecting to the racks inside the chamber and tocords passing over pulleys outside said chamber, whereby the racks maybe raised or lowered. I

L is a supply or waste pipe for the dippingchamber, for admittingalcohol to or drawing it off from the dipping-chamber.

M is the condensing-chamber, containing a coil of pipes through whichcold water is circulated, and upon the outside of which chamber coldwater is also sprayed.

Q is a flexible connection between the dipping-chamber and condenser,which permits the door of the dipping-chamber to be removed withoutbreaking connection with the condenser.

N is the discharge or overflow for the water from the condensing-coil.

O is the pipe for drawing OK the condensed alcohol from the interior ofthe case M.

P is a return-pipe, through which the air, after being relieved of itsalcoholic vapors, is returned to the blower and again sent through thedipping and drying chamber.

In the manipulation of tobacco the leaf is placed on the racks in thebottom of the steamtight chamber G, and the heated dilute alcohol isthen run into this chamber through pipe 4 L until the leaf to be actedon is covered. The alcohol is then drawn off and the racks on which theleaf is hung are raised. The chamber now being full of hanging tobaccodripping wet with alcohol, a blast-gate at each end is opened and astrong draft of air is forced through the chamber bymeans ofa fan orblower. On leaving the chamber this draft of air, bearing with it thevapor or evaporation of the alcohol, is carried by pipes to the condenscr, which I preferably have constructed of galvanized iron. Thischamber is large enough to allow the draft to pass through it at amoderate speed, and as soon as the warm draft of air strikes the coolertemperature it begins to deposit its load of alcohol, which drips fromthe top, sides, and pipes to the bottom of the chamber, where it iscarried off by suitable drainage to a pipe running to a suitablereceptacle prepared for it. At the farther end of the chamber the air,havinglost most of its contained alcohol, passes out and is carriedthrough the return-pipe to the fan, whence it is again forced throughthe dipping-chamber. This circulation is kept up until the alcohol isall evaporated and condensed. Some portion of the alcohol will, however,remain in the air of the chambers and pipes, and at the close of eachdays work a jet of steam should be injected into the circulation, whichwill force the deposit of the remaining alcohol in a very dilute form.The alcohol drawn off from the dipping-chamber after repeated usebecomes foul, and is then recovered by the ordinary process ofdistillation.

I have described the form of condenser which I have found most useful,but do not wish to confine myself to this specific construction, as Ihave obtained good results by passing the air-current through largepipes immersed in cold water with suitable traps to convey away thecondensation.

Theoretically, the pipes and chambers being steam-tight, there should beno loss whatever in using alcohol by this process, but practically thereis some slight waste owing to the impossibility of making any apparatusabsolutely air-tight.

Having thus described my invention, what I claim as new is 1. Theprocess of economically drying tobacco or other substance aftersaturation with alcohol or other volatile liquid, which consists inevaporating the alcohol or volatile liquid by a blast of air, condensingthe volatile vapors by a reduced temperature, and returning the samebody of air through the evaporating or drying chamber again,substantially as described, and for the purpose set forth.

2. The apparatus herein described, consisting of a blower, a dipping anddrying chamber, a condenser, and a return-pipe connecting the condenserwith the blower for the return of the same body of air, all combined andarranged substantially as and for the purpose described.

GOLDSBOROUGH ROBINSON.

Witnesses:

SoLoN O. KEMoN, CHAS. A. PETTII.

